He claims to be a cattleman by trade, but Tomas Renteria has now pleaded guilty to another occupation, carrying out some of the dirty work here in Chicago for Mexican druglord Joaquin "El Chapo" Guzman.

Renteria pleaded guilty to a plot to deliver heroin. Even with the guilty plea, the 46-year-old Sinaloa cartel manager is looking at possible life in prison and a minimum of 10 years.

"He entered a blind plea of guilty today without a cooperation agreement with the government. He pled guilty, he's accepted responsibility for what he has done and you'll hear more at the sentencing but his part of the case is over now," said Damon Cheronis, Renteria's attorney.

Renteria is the first of the defendants charged with Joaquin "El Chapo" Guzman to go down. Assistant U.S. Attorney Thomas Shakeshaft said the government agreed to not ask for a mandatory minimum sentence of 20 years in Renteria's case, but said that was the only concession.

Renteria's attorney reiterated that his client will not be testifying or cooperating with the government. In his plea declaration, Renteria admitted to distributing cocaine and heroin in Chicago between 2005 and 2008.

Charged here as cartel leader, Chicago's Public Enemy No. 1 "El Chapo Guzman," a case involving tons of drugs moved by the Sinaloa Cartel, a group considered responsible for 80 percent of the city's illicit drug supply.

Co-defendant Alfredo Vasquez-Hernandez still plans to go to trial in May, according to his lawyer.

Hernandez is accused of overseeing cartel logistics, including the use of plans and submarine's to transport cocaine shipments.

In early March Hernandez's attorney withdrew an announced guilty plea. He blamed an I-Team report for rumors in jail and in Mexico that his client was cooperating and going to be a government witness, neither of which ABC7 reported.

The major player in this case, "El Chapo" himself, is still locked up in Mexico. The U.S. Justice Department has made known that it wants the kingpin to stand trial in the U.S., possibly Chicago, but so far, there has been no announced decision.